A TEACHER in a Northern Territory school set upon by three teenage students in an unprovoked classroom attack will have his leg amputated next week in a Melbourne hospital.

David Arnold, 64, a 2005 Teacher of the Year award winner, will undergo the life-changing procedure in the Epworth Hospital on Monday after nine operations since the assault in April, 2008 failed to save his leg after it was jumped and stomped on by the students.

"I'm getting ready to go into hospital next week for an amputation, as a result of the attack," said Mr Arnold, who had been a gifted teacher in Katherine High School's special education unit since 2003, and was recognised by the government for developing an intensive learning unit and introducing courses for students that provided them with "meaningful work, pride and dignity".

But Mr Arnold is in an ongoing dispute with the Education Department over compensation, and his assailants, who were aged 13 and 14, escaped justice because the school did not report the matter to police at the time.

A Katherine police spokeswoman yesterday said the matter was dealt with internally by the school in 2008 and was brought to their attention last year.

Inquiries by police have not led to a formal investigation or any charges being laid, she said.

Murray Waycott, a former teacher at Katherine High School, said that on the day of the attack Mr Arnold had been preparing his classroom ahead of the first lesson of the day.

"One particular student was in the habit of pestering David to let him into the classroom before classes started so he could play on the computer," Mr Waycott said. "When David had his back turned that kid went to a sliding door and let in these two other students . . . David told the three of them to leave, and the assault on him unfolded from there. It was unprovoked."

Article From: The Australian